One of the first t things that I do with external hard drives is format them to NTFS.   For compatibility reasons External Hard drives are shipped in the FAT32 Format, that way they are compatible with Windows 98 etc..

Now the reason for the re-format is... I tend to deal with large files sometimes over 4GB this could be archives, video files etc..

the FAT File system has a file size limitation and wont allow you to store 4GB+ Files.

Just a few months ago I went through this process of backing up everything and starting all over its not fun.... especialy when you find out afterwards all the little tweaks that you had made you're system/programs that you have to figure out how to do again.

Sounds like you know what you are doing and quite capable of the task.  If you ever do run into any kind of technical trouble... let me know.